Apparatus for degreasing nonabsorbent articles



L. E. GENT Dec. 2, 1941.

APPARATUS FOR DEGREASING NONABSQRBENT ARTICLES Filed April 4, 1940 w a T S E M F. m m L Patented Dec. 2 1 941 UNITED STATES PATENT OFFICE APPARATUS FOR DEGREASING NON- ABSOBBENT ARTICLES Lionel Ernest Gent, Kjngston-on-Thames, England, assignor to Imperial Chemical Industries Limited, a corporation of Great Britain Application April 4, 1940, Serial No. 327,897 In Great Britain March 23, 1939 2 Claims.

successively smaller height, each compartment being provided with means for vaporizing the solvent therein, while around the walls of the upper part of the tank are cooling coils to condense solvent vapour and a trough to collect the condensate and deliver it to the deepest of the compartments. When the compartments are filled with solvent to the levels of the overflows and the condensing means and vaporizing means are put into operation, a fiow of solvent through the compartments is set up. By always putting the goods to be degreased first in the compartment containing the shallowest bath of liquor and then successively into the deeper baths, thus moving them counter-current to the liquor, the

would rapidly be blocked by the larger particles.

It is an object of the present invention to provide a degreasing apparatus in which the accumulation of swarf and like solids does not interfere with the circulation of solvent. It is a further object of my invention to provide in a degreasing apparatus means by which swarf and like solids so accumulating can be removed withgrease and non-soluble impurities, e. g. swarf,

accumulate in the one compartment in which the goods are first placed, the liquor in the other baths being maintained relatively clean. In modifications of such apparatus the compartment containing the dirtiest liquor is arranged to deliver the solvent to a further compartment used only for vaporizing the solvent. By this arrangement the accumulation of grease, swarf and the like in even the first compartment into i which goods are introduced is reduced.

It is a disadvantage of such types of apparatus, whether provided with a vaporizing compartment or not, that in time swarf and like solid impurities accumulate to an extent which interferes with the operation of the process. Thus where internal steam coils are used as the heating means, sufficient swarf may in time accumulate to interfere with the circulation of solvent around them and thus make the heating inefliout putting the apparatus out of operation.

According to the present invention these objects are achieved by providing in a degreasing apparatus for treating metal and like non-absorbent articles with liquid solvent, a container capable of insertion in a degrea'sing compartment below the solvent level, the bottom of the said container comprising a plurality of baliles forming a labyrinth to catch and retain solids Slllklng 1n the solvent while leaving a tortuous path through which solvent can flow into or out of the container. Preferably the sides of the container extend above the level of the liquid solvent, being then provided with perforations in the walls of the container at or near the level by which solvent can enter or leave the container.

For an apparatus having a number of compartments through which liquid solvent flows in series, the container is inserted in the compartment in which the good are first introduced, and stands in it so that itis immersed in the liquor, while the labyrinth is. above the bottom portion in which the heating surfaces are provided. The apparatus is put into operation in the usual way, whereupon solvent will flow through the various compartments, the labyrinth in the lower part of the container forming no impediment to this circulation. On introducing mto the container the dirty goods to which swarf and like solids adhere, these will be loosened as grease dissolves away, sink into the labyrinth, and there be retained, the base of the compartment where the heating surfaces are located bemg thus kept free from such solids. After a time when a quantity of solid material has accumulated, it 1s readily removed from the apparatus by withdrawing the container. The latter is then emptied of solids and replaced, or another container may be inserted directly and the degreasing process then recommenced. In either case only a very short interruption is necessary to remove the solid material.

The invention is, of course, not restricted to the particular form of degreasing apparatus used above, but may be applied to any such apparatus involving the immersion of goods in a solvent I bath, or to such apparatus wherein the goods are sprayed to remove solids, and the liquor from the spray is collected and redelivered to a pump or still, the container according to our invention being then inserted in the collecting vessel. Again, in degreasing apparatus having a plurality of liquor compartments, 9. container may be inserted in two or more of these compartments.

In another modification of my invention in which the goods are placed in a sieve-like carrier, which is in turn introduced into the degreasing apparatus, the bottom of the carrier may itself comprise the labyrinth, a false bottom on which the goods rest being then provided having large perforations permitting the passage of both solvent and swarf.

The invention will now be more particularly described with reference to the accompanying diagrams, in which:

Fig. 1 represents a sectional elevation of a three compartment degreasing apparatus fitted with the swarf retaining device, and

Fig. 2 represents a sectional elevation of the swarf retaining device on the line AA of Fig. 1, the figure being on an enlarged scale.

In each figure like numerals represent like parts.

In the diagrams the lower part of tank i is divided by partitions i 8 into three compartments, 2, 3 and 4 adapted to contain liquid solvent, and a vaporizing compartment 5, each having a steam coil 6 to heat the solvent. Around the perimeter of the upper part of the tank i are condensing coils 8 which can be provided with water or other cooling liquid by means not shown, and a trough 9 immediately below coils 8 by which condensate from these coils can be collected and delivered by pipe It to the lower part of compartment 2 remote from vaporizing compartment 5.' The heights of the successive partitions i8 diminish towards compartment 5, and near each on the side toward that compartment are bailles l1 extending nearly to the base of the compartments 3, 4, and respectively. A circulation of solvent through the apparatus can thus be set up from compartment 2 through compartments 3 and 4 into compartment 5 where it is vaporized, to be condensed on coils 8 and returned via trough 9 and pipe iii to compartment 2. In each of compartments 2 and 3 is a grating l on which goods to be degreased can be supported.

In compartment 4 there is placed the swari retainer IS with which my invention is concerned. The swarf retainer has dimensions not much less than those of the compartment 4 so that the space available for the degreasing operation is not appreciably diminished by its insertion; it is supported above heating coil 6 by legs i6, and extends to above the solvent level determined by the partition I! separating compartments 4 and 5. At the level of the solvent the retainer is fitted with gauzes l4 which permit solvent to flow into or out of it The bottom of the swarf retainer is formed of three bailles l I, I2 and I3; ii and i3 form troughs with the respective sides of the retainer it while the central baiiie I2 is itself trough-like, and its edges overlap those of baiiles II and I3 but are spaced from them, leaving gaps 2!. The baiiles thus form a labyrinth through which solvent can flow by a in the solvent are caught in one or other of the troughs formed by the baifles.

The troughs are lined with removable gauzes 20 to facilitate removal oi the solids so accumulating and a grating I! may also be provided immediately above the baiiies II, II and II to support goods placed in the apparatus. Alternative means for removing the accumulated 'swarf may also be provided; for example the base of each trough may be formed of a removable fine meshed gauze sliding in slots formed in the trough.

In operation, the retainer is put in compartment 4, and the solvent circulation is set up as described above. Solvent coming from compartment 3 is forced by baiiie I! in compartment 4 to travel to the bottom of that compartment, whence it travels upwards, passing into the retainer through the spaces 2| between baiiies ii and I2, and i2 and i3 respectively, out through gauzes l4, and thence into vaporizing compartment 5.

The goods to be treated, contaminated from previous operations with grease and in' general with swarf or other solid materials, are placed in theswarf retainer it, when grease is dissolved ed; at least the major part of the solid particles are thus released and fall through the solvent, and are caught in baflle I2, 01; in one or other of the troughs formed by baflles Ii and I3 respectively with the sides oi. the retainer; gauzes l4 prevent particles in the upper layers of the liquid being carried out of the retainer before they can sink. After the goods have been treated in this compartment, they are removed substantially free from adherent solids and contaminated with only small amounts of grease which are removed by treatment in compartments 3 and 2 in the usual manner.

As increasing quantities of goods are treated, solids accumulate in the troughs of the retainer leaving the space below it where the heating coil is situated substantially free of solids, and leaving ample room for the passage of solvent from the region of the heating coils into the retainer. In time it becomes necessary to empty the retainer and this can readily be done by withdrawing it from compartment 3, removing, empty g and replacing gauzes 20 and replacing the retainer in the compartment.

In a further form of my invention instead of shaping the gauzes to line the troughs formed by the baiiies, the labyrinth may be-formed of horizontal and vertical members, the horizontal members being of sheet metal or other impervious material, while the vertical members are at least in part formed of gauze. Thus the horizontal members may comprise a ledge around the perimeter of the retainer, and a plate corresponding in shape and size to the opening left by the ledge and spaced above it by a short distance, while the vertical member is formed of wire gauze extending around the plate and reaching from the plate down to the ledge. Suitably the gauze is permanently joined to the plate, and detachably joined to the ledge, e. g. by nuts and bolts, so that plate and gauze may be removed for cleaning purposes. With such' an arrangement the solids sinking in the solvent will be retained on the horizontal members, leaving the solvent free to flow through the gauzes, which, being vertical will not become blocked with the solids.

I claini:.

1. A swarf retainer adapted to be removably inserted in a solvent chamber of a degreasing apparatus, said retainer comprising an open-top vessel having side walls and a bottom portion attached thereto, said bottom portion comprising a plurality of trough-shaped baflles serving to catch and retain solids sinking in the solvent, said baflles having overlapping edge portions forming therebetween a tortuous passageway for the flow of solvent into and out of said retainer.

2. A swarf retainer adapted to be removably inserted in a solvent chamber of a degreasing apparatus, said retainer comprising an open-top 10 vessel having side walls and a bottom portion attached thereto, said bottom portion comprising a plurality of trough-shaped baflles serving to catch and retain solids sinking in the solvent, said bafiles having overlapping edge portions forming therebetween a tortuous passageway for the flow of solvent into and out of said retainer,

and gauzes removably attached to said baflles to facilitate removal of swarf accumulating thereon.

' LIONEL E. GENT. 

